Between 1989 and 1996, Blahous worked as a legislative aide to Senator Alan Simpson of Wyoming; he was his Congressional Science Fellow in 1989-1990 and Legislative Director in 1994-1996 (sponsored by the American Physical Society). After Simpson's retirement, Blahous served from 1996 to 2000 as a Policy Director for Senator Judd Gregg of New Hampshire. From June 2000 through February 2001 he served as the Executive Director of the Alliance for Worker Retirement Security. From 2001 to 2007, he served as a Special Assistant to the President for Economic Policy, during which time he also served as Executive Director of the bipartisan President's Commission to Strengthen Social Security.[3] He helped create President George W. Bush’s failed plan to let people put some of their payroll taxes into personal retirement accounts.[4] From 2007 to 2008, he held the position of the Deputy Director of the National Economic Council. After the end of George W. Bush's second term in office in January 2009, Blahous joined the Hudson Institute as a Senior Fellow.[5] In 2010, Blahous left the Hudson Institute and became a Research Fellow at the Hoover Institution.[6]

His ideas about Social Security reform issues are explained in Reforming Social Security for Ourselves and Our Posterity, a book he published in September 2000. Blahous' second book, Social Security: The Unfinished Work, was published by Hoover Institution Press in November 2010, and a third, Pension Wise: Confronting Employer Pension Underfunding - And Sparing Taxpayers the Next Bailout, was released by the same publisher in December 2010.[7]

In the 2016 hearings of the Senate Finance Committee, Democrats opposed his second term as public trustee of Social Security, because, they said, he undermined public confidence in the program by exaggerating its problems. Sen. Elizabeth Warren (D-MA), said he was “an anti-government zealot.” Sen. Chuck Schumer (D-NY), said that his academic career shows that he is “personally ideologically opposed to the fundamental promise of Social Security.” The committee voted to recommend reconfirmation by 14-12, with all Democrats voting against him.[4][8]